The ultrasound image clearly demonstrates a thickened and elongated pyloric muscle with a visible channel, which is characteristic of hypertrophic pyloric stenosis (HPS). This condition is most commonly seen in male infants between 2 and 8 weeks of age who present with non-bilious projectile vomiting, dehydration, and a palpable “olive-like” mass in the right upper quadrant.

Ultrasound is the imaging modality of choice and is highly sensitive and specific for diagnosing pyloric stenosis.

Key sonographic criteria for HPS:

Muscle thickness >3 mm

Pyloric channel length >15–17 mm

“Target sign” or “doughnut sign” on transverse imaging (concentric rings)

“Cervix” or “railroad track sign” on longitudinal imaging (elongated canal with echogenic center)

Differentiation from other options:

A. Intussusception: Also shows a target sign, but it occurs in the right lower quadrant or periumbilical region, not in the gastric antrum.

C. Hydronephrosis: Refers to dilation of the renal pelvis and calyces — not gastrointestinal.

D. Gastritis: May show gastric wall thickening but lacks the distinct elongated, thickened pyloric muscle seen here.